/* ==========================================
 * JGraphT : a free Java graph-theory library
 * ==========================================
 *
 * Project Info:  http://jgrapht.sourceforge.net/
 * Project Creator:  Barak Naveh (http://sourceforge.net/users/barak_naveh)
 *
 * (C) Copyright 2003-2006, by Barak Naveh and Contributors.
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation,
 * Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
 */
/* -------------------
 * RandomGraphHelper.java
 * -------------------
 * (C) Copyright 2003-2006, by Michael Behrisch and Contributors.
 *
 * Original Author:  Michael Behrisch
 * Contributor(s):   -
 *
 * $Id: RandomGraphHelper.java,v 1.2 2007/05/22 15:52:59 kjellw Exp $
 *
 * Changes
 * -------
 * 13-Sep-2004 : Initial revision (MB);
 *
 */
// package org.jgrapht.generate;
package org.jgrapht.experimental;

import java.util.*;

import org.jgrapht.*;

/**
 * UniformRandomGraphGenerator generates a <a
 * href="http://mathworld.wolfram.com/RandomGraph.html">uniform random graph</a>
 * of any size. A uniform random graph contains edges chosen independently
 * uniformly at random from the set of all possible edges.
 * 
 * @author Michael Behrisch
 * @since Sep 13, 2004
 */
public final class RandomGraphHelper {
	// ~ Static fields/initializers
	// ---------------------------------------------

	private static final Random randSingleton = new Random();

	// ~ Constructors
	// -----------------------------------------------------------

	/**
	 * .
	 */
	private RandomGraphHelper() {
	}

	// ~ Methods
	// ----------------------------------------------------------------

	/**
	 * @see GraphGenerator#generateGraph
	 */
	@SuppressWarnings("unchecked")
	public static void addEdges(Graph target, List sourceVertices,
			List destVertices, int numEdges) {
		int sourceSize = sourceVertices.size();
		int destSize = destVertices.size();

		for (int i = 0; i < numEdges; ++i) {
			while (target.addEdge(sourceVertices.get(randSingleton
					.nextInt(sourceSize)), destVertices.get(randSingleton
					.nextInt(destSize))) == null) {
				;
			}
		}
	}

	/**
	 * .
	 * 
	 * @param target
	 * @param vertexFactory
	 * @param numVertices
	 * 
	 * @return
	 */
	@SuppressWarnings("unchecked")
	public static Object[] addVertices(Graph target,
			VertexFactory vertexFactory, int numVertices) {
		Object[] vertices = new Object[numVertices];

		for (int i = 0; i < numVertices; ++i) {
			vertices[i] = vertexFactory.createVertex();
			target.addVertex(vertices[i]);
		}

		return vertices;
	}
}

// End RandomGraphHelper.java
